Electric drill



Ogt. 27, 19421 M Dem ELE'CTRIC DRILL Filed April 14, 1941 3 Sheets-Sheet l INVENTOR. 6/770 Max e! D ATTORNEY.

Oct. 27, 1942. M. J. DEMO ELECTRIC DRILL Filed April 14, 1941 3 Sheets-Sheet 2 Oct. 27, 1942.

M. Jfibsmo 2,299,881

ELECTRIC DRILL Filed April 14, 1941 3 Sheets-Shet 3 -12211 ak/daz- 1N VENTOR.

/Vm efDe/no I ATTORNEY.

Patented Oct, 27, 1942 UNITED STATES PATENT OFFICE ELECTRIC DRILL Max J. Demo, Julian, Calif.

Application April 14, 1941, Serial No. 388,445 l f v 14 Claims. (or 255-47.)

My invention relates to an electric drill,,more

particularly an electric drill in, which the tool operating shaft reciprocates and rotates while being fed outwardly ofthe drill land the objects of my invention are:

First, to provide an electric drill of this class in which the hammer member, the tool operating shaft 'andthe feed screw all operate on a common axis;

Second, to provide an electric drill of this class in which water or air is passed through the feed screw thereof in concentric relation with the tool operatingshaft of my electric drill;

Third, to provide an electric drill of this class in which rotation, reciprocation and outward shifting ofthe tool operating shaft is accomplished by means operating on a common axis providing compact relation of the operating mechanism of my electric drill;

Fourth, to provide an electric drill of this class in which a water and air pump is positioned and arranged to supplywater and air under pressure to the tool in connection with my electric drill providing an arrangement whereby auxiliary pumps are not needed drill; 7

Fifth, to provide an electric drill of this class which is entirely operated by electric power delivered directly to my electric drill only;

Sixth, to provide an electric drill of this class in which the hammer members act upon a tool operating shaft clutch which is so arranged that it frictionally engages the tool operating shaft and imparts hammer action thereto when said tool operating shaft is feeding outwardly of said clutch and rotating at the same time; I

Seventh, to provide an electric drill of this classwhich is very efficient, easy to operate, relatively light and admirably adapted for use in various drilling operations executed in confined positions; l

Eighth, to provide an electric drill of this class in which automatic trip means stops the rotative operation of the feed screw when it arrives at the limit of travel in either direction;

Ninth, to provide anelectric drill of this class which may be used only as a rotational drill or as both a rotational and hammer drill;

Tenth, to provide an electric drill of this class in which a pump is enclosed and arranged for use as a common means in supplying water or air to the tool in connection with my electric drill; Eleventh, to provide a novel electric drill of this class;

to operate my electric Twelfth, to provide an electric drillof this class in which a light is provided for use in illuminating dark places in which my electric drill is used;

Thirteenth, to provide an electric drill of this class in which'outwardly extending portions of the tool operating shaftare' covered when passing inwardly and outwardly of myelectric drill;

Fourteenth, to provide an electric drill of this class in which substantially all the operating mechanism is enclosed preventing breakage of the same'; and

Fifteenth, 'to' provide an electric drillof this class which is 'very simple and economical of construction'in proportion to its utility, efficient in its action and which will not readily deteriorate and get outof order;

With these and'other objects in view as will appear hereinafter, my invention consists of certain novel features of construction, combination and arrangement 'of parts and portions as will be hereinafter described in detail and particularly set forth in the appended claims, reference being had to the accompanying drawings and to the characters of reference thereon which form a part of this application in which:

Figure 1 is a fragmentary longitudinal sectional view of my electric drill taken from the line of Fig. 2 showing parts and portions in elevation to facilitate the illustration; Fig. 2 is a transverse sectional view taken from the line 2-2 of Fig. 1; Fig. 3 is an enlarged fragmentary sectional view of one end of my electric drill taken from the line 3-3 of Fig. 5 showing parts and portions in elevation to facilitate the illustration; Fig. 4 is an enlarged fragmentary sectional view of the opposite end of my electric drill. taken on substantially the same plane as Fig. 3 showing parts and portions in elevation to facilitate the illustration and also showing bydash lines varying positions of parts and 6--6'of Fig. 4 showing portions broken away to facilitate the illustration; Fig. 7 is a fragmentary sectional view taken from the line 1-1 of Fig. 3; Fig. 8 is a reduced detail sectional view of the cam member of my electric drill taken from the line 8-8 of Fig. 7; Fig. 9 is a reduced sectional view of the cam member of my electric drill taken from the line 9-9 of Fig. '7 showing the opposite side of the cam member from that shown in Fig. 8; Fig. 10 iS '2, plan sectional view taken from the line. |l l|0 of 4, and Fig. 11

is a fragmentary sectional view taken from the line II-II of Fig. 10.

Similar characters of reference refer to similar parts and portions throughout the several views of the drawings:

The casing members I, 2, 3, 4, 5 and 6, journal members 1, 8, 9, I and II, rotor I2, rotor shaft I3, tool operating shaft I4, feed screw I5, feed screw engaging nut I6, feed screw swivel connection I1, gears l8, I9, 20, 2|, 22, 23 and 24, 1

gear shaft 25, gear operating clutch members 26, 21, 28 and 29, clutch operating trip levers 30 and 3|, pump 32, pump inlet conductor 33, pump outlet conductor 34, pump inlet valve 35, valve operating lever 36, valve operating link 37, water inlet conductor 38, air inlet conductor 39, air cleaner 4!], fan 4I, armature brushes 42, motor field 43, hammer members 44 and 45, hammer operating spring 46, hammer operating cam 41, tool operating shaft clutch 48, clutch operating lever 49, clutch control link 53, clutch control ring 5I, tool operating shaft cover 52, slip ring 53, main control levers 54 and 55 and the light bulb 55 constitute the principal parts and hertions of my electric drill.

The casing member I is arranged to partially enclose the front end of my electric drill and it is provided with an opening Ia therein through which extends the tool operating shaft I4 together with the tool operating shaft cover 52. Positioned in the front upper side of the casing member I is an opening Ib in which is positioned a lens Ic behind which is positioned the light bulb 56 which is arranged to emit light through the lens I c forwardly from the front end of my electric drill.

Positioned in adjacent relation with the casing member I is the hollow cylindrical casing member 2. Interposed between the end of the casing member 2 and the casing member I is the journal member I through the central portion of which extends the tool operating shaft I4, as shown best in Fig. 3 of the drawings. The one end of the casing member 2 is connected in the casing member I by means of the annular portion Id which surrounds the end of the casing member 2, all as shown best in Fig. 3 of the drawings. The opposite end of the casing member 2 from the casing member I is surrounded by the end of the casing member 3 in which the motor field 43 is mounted, as shown best in Figs. 1, 3 and 4 of the drawings. Interposed between the casing members 2 and 3 is the journal member 8 which provides a bearing at its central portion for the rotor shaft I3, as shown best in Fig. 3 of the drawings.

Secured to the opposite end of the casing member 3 from the casing member 2 is the hollow cylindrical casing member 4. Interposed between one end of this casing member 4 and the casing member 3 is the journal member 9 which forms the bearing for the rotor shaft I3 at the opposite end of the rotor from the journal member 8. cured to the opposite end of the casing member 4 from the casing member 3 and surrounding the same is the casing member 5, as shown best in Fig. 4 of the drawings.

Positioned at the opposite end of the casing member 4 from the journal member 9 is the journal member II]. This journal member I0 provides a bearingat its central portion for the outer side of the rotor shaft I3 and also forms a support for the pump 32, as shown best in Fig. 4 of the drawings. This journal member I0 also provides a bearing for the gear shaft 25 at its one end, as shown best in Fig. 4 of the drawings.

The journal member I I is secured on the lower inner side of the casing member 5 and is arranged to provide a bearing for the feed screw I5, all as shown best in Fig. 4 of the drawings. This journal member I I also provides a support for the gear 22 as shown in Fig. 6.

The casing member 5 is provided with an up wardly extending hollow portion 5a arranged to contain and support the main control levers 54 and 55 together with their operating mechanism. This casing member 5 is also curved at its rear portion and secured thereon is the curved casing member 6 which forms the rear end of my elec tric drill, all as shown best in Fig. 4 of the draw mgs.

The rotor I2 is a conventional electric motor armature and is arranged to revolve and turn the rotor shaft I3 which is a hollow cylindrical shaft journalled in the journal members I0, 9 and 8, as shown best in Figs. 3 and 4 of the drawings.

The rotor shaft I3 is provided with an eccentric cam portion I3a thereon, as shown best in Fig. 4 of the drawings. This eccentric cam portion I 3a is arranged to operate the pump 32, which is a substantiallyconventional cam operatedcylinder pump. Fixed on one end of this rotor shaft I3 is the gear 24 which is in meshed relation with the gear 23 on the gear shaft 25. As shown in Fig. 3 of the drawings the rotor shaft I3 is provided with inwardly and outwardly extending key portions I3b and I3c. These key portions I3b and I30 are shown in cross section in Fig. 7 of the drawings. The key portion I31) is arranged to engage the hammer members 44 and 45 and the inwardly extending key portion I 30 is arranged to engage a slotted portion I4a in the upper side of the tool operating shaft I4, as shown in Figs. 3 and 7 of the drawings.

The tool operating shaft I4 is reciprocally mounted in the rotor shaft I 3 and is guided therein by the key portion I 30, as hereinbefore described. This tool operating shaft I4 at its end portion I4b, which extends outwardly of the end of my electric drill is arranged to support a conventional drill steel retaining chuck, not shown in the drawings and which is no part of my present invention. This tool operating shaft I4 is also provided with an annular groove portion Me in which is positioned the slip ring 53. Secured to this slip ring 53 by means of the sleeve 53a is the tool operating shaft cover 52. This tool operating shaft cover 52 is preferably made of leather, or other suitable material and is arranged in the form of bellows and is secured at its inner end to the journal member 'I, all as shown best in Fig. 3 of the drawings. This tool operating shaft cover 52 provides a cover for the tool operating shaft I4 at the portion thereof extending outwardly from my electric drill at the front end thereof. The tool operating shaft I4 on its outer side is provided with annular groove portions I 4d. These annular groove portions I4d are angular in cross section and diverge toward the rear end of my electric drill. These annular groove portions I4d are arranged to be engaged by the teeth 48a of the tool operating shaft clutch 48, as shown best in Fig. 3 of the drawings. Near the end portion I4?) of this tool operating shaft I4 and centrally thereof is an opening Me. This opening Me is arranged to conduct air or water outwardly to the drill steel or other tool used in connection with the drill operating shaft I4. This tool operating shaft I4 is provided with an enlarged bore I4) communieating with the opening I46, as shown best in shownbest in Figs. 4 and 6 of the drawings.

drawings.

I Fig. 3.0131 the drawings. Reciprocallyand revolublyimounted inthis enlarged bore l4) of the tool operating .shaft I4 is the feed screw/15. This feed "screw 15 is arranged in screw threaded engagedrelationwith the feed screw engaging nut operating shaft l4 neartherearendthereof 'as This feedscrew engagingnut I6 is reciprocally mounted in the enlarged bore portions 14g of the tool operating shaft l4 and is keyed in the tooloperating shaft 14 by means of the key portion 6a,

all as shown best in Fig. 6 of the drawings; En-

gagingopposite sides of the feed screw engaging nut l6 iare coil compression springs-which are held in place by means of the nut|4h screw threaded. in the rear end. of the tooloperating shaft 0|4. Thefeed screw J5 isa conventionally formed helical screw and is provided with a central: bore|5a therein arranged to conduct air or water, as shown best in Figs. 3 and 40f the drawings. Positioned on the forward end of this feed screw I5 is a packing groove portion |5b which engagesthe enlarged bore IU of the tool operating shaft M, as shown best in Fig.3 of the Secured on this feed screw I5 infixed relation therewith" adjacent thegear 24 is the gear I8.

I Securedin. fixed relation with the feed screw IS on the opposite side of the journal member H from the gear I8 is the gear l9. Secured on the extending end of *the feed screw l5 adjacent the gear l9 isthefeed screw swivel connection l1, which is a conventional liquid conducting swivel connection member arranged to conduct liquid irom the pump outlet conductor 34 to the internal bore |5d of the feed screw I5," all as shown best in Fig.4 of the drawings.

The gear 'is freely revolubly mounted on the gear shaft and is in meshed relation with the gear 22 supported by the journal member II as shown best in Figs. '4 and 6 of the drawings. The gear. 2| is freely revolubly mounted on the gear shaft 25 and is inmeshe'd relation with the gear l8; as shown' best in Fig. 4 of the drawings. The gear 23-is fixed 'on the gear sh'aft25 and is arranged inmeshed relation with the gear Men the rotorshaft l3. The gear shaft 25 is revolubly mounted in the journal member III at its oneend. and is journalled in the casing member 5 at its other end, all as shown best in Fig. 4 of the drawings. 4 The clutch memberlfi is secured to the gear 20 and is arranged to engage the clutch member 21 whichis'fixed on the gear shaft25.

The clutch member28 is arranged infixed relation with the gear 2| and is arranged to engage the. C111fiCh member 29. This clutch mem ber 29 is in,fixed relation with the gear 23 and the gear shaft 25. Itwill be'here noted that I have positioned compression springs between the clutch members Hand-:21 and between the clutch members 28 and 29 so that the clutch members 26 and 21 cannot be engaged at the same time theclutchmembers 28 and 29 are engaged.

The clutch operating trip lever 30 is arranged to engage one side of the gear l8 in opposed rej lationqto the clutch operating trip lever 3|, as shownbestinFig. 4 of the drawings. The clutch operating triplever 30 ispivotally mountedon a. bolt 30a and is arranged to engage the. clutch member 21 for shifting the same awayfrom the clutchmember, 26 when the feed screw l5'h'as forced the tool operating shaft |4 inwardly to the clutch'operating trip lever 30am! is arranged toiforce the clutch member 28 out of engagement with the clutch member 29 when the feed screw 5 has shifted the tool operating shaft l4 outwardly to' the limits of its travel relatively with the key portion |3c of the rotor shaft l3 inthe slotted portion l4aof said tool operating shaft |4,1allas shown bestin Figs. 3 and 4 of the drawings. Thisclutch' operating trip lever 3| is journalled on the -bolt 30aand is integral with the clutchoperating lever 30, as shown best in Figs. 4 and 6 of thedrawings. clutch operating trip lever 3| is arranged to engage the side of' the gear 2| for shifting the clutch member 28 out of engagement with the clutch member 29, as indicated by dash lines in Fig. 4 of the drawings. The bolt 30a is supported in connection with the lower side of the casing 5,-a'11 as shown best in Fig. 4 of the drawings.

The pump 32, as hereinbefore described, is operated by an eccentric cam portion |3a on the rotor shaft |3 and this pump 32 is a substantially conventionahcylinder pump having a substantially manifold" shaped tubular pump inlet conductor 33 communicating with thepump inlet valve'35, as shown bestin Fig. 4 of the drawings. This pump 32 is also provided with a pump outlet conductor34 which is of hollow tubular material and substantially the form of a manifold, as shown best in Fig.4 of the drawings. Communicatingwiththis pump outlet conductor 34 is a tubular member 34a extending to the feed screw swivel connection member H and communicating therewith for feeding liquid or air from the pump 32 into the internal bore |5a of the feedscrew l5.

The pump inlet valve 35 is a two-way valve and-is provided with a water inlet conductor 38 and {an air inlet conductor39. Intermediate the air inlet conductor 39 and the valve 35 is a small air-cleaner 49. This air cleaner is substantially conventional'iniorm and function. The pump inlet valve 35 is'p'rovided with an operating lever 35aconnecte'd with which is the 'valve operating link 31' which extends to the upper side of the casing4of my electric drill. Pivotally mounted on the upperside of the casing'4 is the valve operating lever 36 withwh'ich is connected the valvebperating link 31, all as shown best in Fig. 4 of the drawings.

Thefan 4| is fixed on the outer side of the rotor shaft l3 intermediate th journal member 9 and the pump 32, asshown best in Fig. 4 of the drawings. fan 4l is arranged to provide a circulation ofjair through the openings 9a in the journal member 9 around the rotor |2 for cooli ngi the moto'roi my electric drill. This fan 4| also circulatesair around the pump 32 for coolingthejsame 1 The casing 4 is provided with air circulation opernngs, 4a therein; as shown best in Fig. 4 of th'eldrawingsl Which openings 4d. are positioned The upper end of this secured on the journal member 9, as shown best in Fig.4 of the drawings.

The motor field 43 is secured on the inner side of the casing member 3 in concentric relation aroundzthe rotor I2, as shown best in Figs. 1, 3 and 4 of the drawings.

The hammer member 44 is reciprocally mounted on the rotor shaft I3 forwardly of the journal member 8 and is guided by the key portion I3b which extends into the hammer 44, as shown best in Fig. 7 of the drawings. This hammer member 44 is circular in cross section, as shown in Fig. 7 of the. drawings, and connected therewith is a roller bearing 44a. This roller bearing 44a engages .a recessed track portion 21a in the cam member 41, as shown best in Figs. 3, 8 and 9 of the drawings. Referring particularly to Figs. 8 and 9 of the drawings, it will be observed that the roller bearing 44a in the recess track portion 41a of the cam member 41 forces the hammer member 44 backwardly against the compression spring '46 due to the angular helical relation of the recess track portion 41a in the cam member 41. When the roller bearing 44a reaches the abrupt turn 41b of the recess track portion 41a, the hammer member 44 is instantly pressed forwardly toward the hammer member 45 by the hammer operating spring 46. It will therefore be understood that each time the rotor shaft I3 revolves, the hammer member 44 reciprocates backwardly and forwardly on the rotor shaft I3 guided thereon by the key portion I3b. The hammer member 45 is arranged to be struck by the hammer member 44 with each revolution of the rotor shaft I3. This hammer member 45 is reciprocally mounted on the rotor shaft I3 and guided thereon by means of the key portion I31). Secured to this hammer member 45; is the tool operating shaft clutch 48. This tool operating shaft clutch .48. in connection with the hammer member 45, is maintained in rearwardly compressed relation toward the hammer member 44 by means of the spring 45a.

The tool operating shaft clutch 48 is provided with inwardly extending teeth 48a which are arranged to engage the annular grooves I4d of the spool operating shaft l4, as shown best in Fig. 3 of the drawings. The outer ends of these teeth 480. are pivotally mounted in connection with curved levers 48?). These curved levers 481) are stationarily pivoted in connection with the tool operating shaft clutch 48 by means of the pins 480.

Interposed between the extending ends of the levers 48b and the tool operating shaft clutch 48 are compression springs 48d. These compression springs 48d tend to force the extending ends of the levers 48b outwardly from the tool operating shaft clutch 48 maintaining certain engaged relation of the teeth 48a with the groove portions Md in the outer side of the tool operating shaft I4, all as shown best in Fig. 3 of the drawings.

The clutch control ring is positioned in surrounding relation with the curved levers 48b of the tool operating shaft clutch 48, and this clutch control ring 5| is connected with the clutch operating lever 49, as shown best in Figs. 1, 2 and 3 of the drawings. This. clutch operating lever 49 is pivotally mounted on a bolt 49a in rigid connected relation with the casing 2, as shown best in Figs. 2 and 3 of the drawings.

Pivotally connected with the extending ends of the clutch operating lever 49 is the clutch control link 50, as shown best in Figs. 1. 3 and 4 of the drawings. The clutch control link 50 extends backwardly from the clutch operating lever 49 through the journal member 8, the motor field 43 and thejournal members 9 and I0 and this clutch control link is arranged to be engaged by the main control lever 54 at its opposite end from the clutch operating lever 49, as shown best in Fig. 4 of the drawings.

The main control lever 54 is arranged in pivoted relation with the casing 5 and is pivotally supported on a bracket 54a below the upper side of the casing 5, as shown best in Fig. 4 of the drawings. The lower end of this control lever 54 is arranged to engage the gear 2| at its one side and the clutch member 21 at its other side for shifting the clutch member 28 into engagement with the clutch member 29 and the clutch member 27 into engagement with the clutch member 26 respectively. This main control lever 54 is also arranged to force the clutch control link 50 backwardly for pivoting the clutch operating lever 49 and shifting the clutch control ring 5| over the curved portion of the levers 48b for pivoting the same and releasing the teeth 4811 from the annular groove portions I4d of the tool operating shaft I4, The main control lever 55 is provided with a cam portion on its lower end and is arranged to shift the latch member 55a into engagement with the clutch control link 50 for latching the same in position when shifted backwardly by the main control lever 54. The main control levers 54 and 55 are provided with detent members 55a which are arranged to engage recessed portions 550 in the casing member 5 for holding said main control levers 54 and 55 in certain positions for controlling the operating mech anism of my electric drill.

The operation of my electric drill is substantially as follows: When it is desired to use my electric drill for drilling holes in rocks or other substances, a conventional drill steel is arranged in connection with a chuck on the end of the tool operating shaft I4. Said chuck is not shown in the drawings and is no part of my present invention. The operator starts my electric drill by operating a switch handle 51 on the upper side of the casing 3 of my electric drill. When the electric switch 51 is operated, the rotor I2 revolves inside the motor field 43 carrying with it the rotor shaft I3 revolving the eccentric cam I3a. and operating the pump 32. At the same time the hammer member 44 is reciprocated-on the rotor shaft I3 by means of the cam 41, as hereinbefore described. The hammer member 44 strikes the hammer member 45 which is connected with the tool operating shaft clutch 48. The teeth 48a in engagement with the groove portions I4d of the tool operating shaft I4 force the tool operating shaft I4 outwardly with each operation of the hammer member 44. It will be here noted that the key portion I3c of the rotor shaft I3 in connection with the slotted portions I4a of the tool operating shaft I4 revolves the tool operating shaft I4 in conforming relation with the rotor shaft I3. The tool operating shaft clutch 43 revolves with the hammer member 45 on the rotor shaft I3 and the compression springs 48d force the teeth 48a into certain engaged relation with the annular groove portion I4b of the tool operating shaft I4. The compression spring 450. is arranged to force the hammer member 45, together with the tool operating shaft clutch 48, toward the hammer member 44 as it passes toward the rotor l2 with each revolution thereof, advancing the teeth 48a from one of the grooves I4d to the next groove M11 in the tool operating lution thereof which revolves the gear I8 inafcorresponding direction to the gear 24and the gear ratiobetween the gear 2t and I8 is so arranged'that the gear I8 revolves faster in the same direction thanthe gear 24. Therefore; the, feed screw l5 inconnection with the gear I8 revolves slowly within the tool operatingshaft l'4' in relation with the revo-' conforms to the revolution of the rotor'shaft13l It will be obvious that as'th'e feed screw I5 revolves faster thanthe tool operating shaft l4,

the feed screw engaging nut lioper'ating on the screw threads of the feed screw l5 shifts the tool operating shaft outwardly away from the gear 18 toward the front end of my electric drill. When the tool operating shaft-l4 reaches its limit of travel and engages the end of the keyportion I30 of the rotor shaft I3, thelgear [8 tends to shift backwardly toward the journal member H pivoting the clutch operating lever 3| ,backwardly and forcing the clutch member 28 out of engagement with the clutch member29 and permitting the gear shaft to .revolve freelywithin the gear 2| which stops the operation of the feed screw 15 andfthe outward movement of the tool operating shaft I4 in operative relation therewith. When it is desired to retractthe tool operating shaft M the lever 54 is shifted forwardly at its upper end forcing the clutch member 21 into engagement with the clutch memberr26 so that the gear 20 is revolved in mesh relation with the gear 22 operating the gear I9 in mesh with the gear 22 in the opposite ,direction from the gear 24 on the rotor shaft 14. It. will be obvious that the feed screw l5 retracts the-tool operating shaft l4mueh faster than the-tooloperating shaftis fed outwardly due tothearrangement of the gears whereby the gear, l9 operates in the reverse direction from the gearl24. When the clutch members 21 and 26* are engagedand the gears 20, 22 and I! are operating the feed screw l5, the tool operating shaft l4 passes'backwardly toward the gear 18 and when the tool operating shaft 14 reaches its limit oftravel and engages the end of the key portion.l3c of the: rotorshaft I3, the gear l8 tends to shift-towardthe gear 24 pivoting thelever and disengagingthe clutch member 21 from the clutch member-26 stopping thereverse operation of the' feedvscrew l5 and preventing breakage of the mechanism of my electric drill. It will be herenoted that the main controllever 54 is arranged to engage the gear 2| and the clutch 2 1 at its opposite side for shiftingthe clutch members Zl'and 28 into en-L gagement with the 'clutch members 26 and 29,

respectively. 1 i V, In connection with the pump inlet conductor 33 is the pump inlet valve 35. This pump inlet valve 35 is controlled by thelever 36 and is arranged to admit either, water or air to the pump 32 so that water or air may beconducted through feed screw 15 and is supplied to the drill steel in connection with my electric drill.

. It will be here noted that when the hammer lar construction, combination and arrangement of parts and 'portions,I do not wish to be limited to this particular construction, combination and arrangement, but desire to include in the scope of 'my invention the construction; combination and arrangement substantially asset forth in the appended claims. V f 1 Having thus described my invention, what I claim as new and desiretosecure by Letters Patentis:

1. In an electric drill of the class described, the combination of a casing, an electric motorvin said casing, a hollow rotor shaft for saidmotor, a tool operating shaft reciprocally mounted in said rotor shaft, a feed screw internally of said tool operating shaft and operatively engageable thereand a pump operated onfithe outer side" of said rotor shaftarrangedfto force substance through saidffeed screw; i l 3 2. man electric drill of theclass described, the combination of a casing, an electric motor in said casing, a hollow rotor shaft for said motor, .a tool operating shaft reciprocally mounted in said rotor shaft, a feed screw internally of said tool operating shaft and operatively engageable therewith for longitudinally shiftinglsaidutool operating shaft-in said-y rotor shaft, a stationary cam member in said casing anda hammer member operated by said rotor shaft and engageable with said cam member. 7 i

3. In an electric drill of the class described, the

combination of a casing, an electricv motor in said casing a hollow rotor shaft for said motor, a tool operating shaft reciprocally mounted in said rotor shaft, a feed screw internally of said tool operating shaft and operatively engageable therewith for longitudinally shifting said tool operating shaft in said rotor shaft, astationary cam member in said casing,ahammer member operated by said rotor shaft and engageable with said cam member, and a tool "operating shaft clutch frictionally engageable with said tool'operating shaft and en'gageablewith said hammer member.

- 4:. In an ele'ctricdrill of the class described, the combination of acasing, an electric motor in said casing, "a hollow rotor shaft for said motor, a tool operating shaftreciprocally mounted in said rotor shaft, a feed screw internally of said tool operatingshaft and operativelyengageable there- ,with forlongitudinally shifting said tool operating shaft in said rotor shaft, a stationary cam member in said casing, a hammer member operi atedby said rotor shaft and engageable with said cam member, and a tool operating shaft clutch 'frictionally engageable with said tool operating shaft and engageable with said hammer member,

said tool operating shaft clutch freely shiftablein one direction rl-ativelywit'h said tool operating shaft.

5. In an electric drill of the class described,

the combination of a casing, an electric motor in said casing, a hollow rotor shaft for said motor, a tool operating shaft reciprocally mounted in said rotor shaft, a feed screw internally of said tool operating shaft and operatively engageable therewith for longitudinally shifting said tool operating shaft in said rotor shaft, a stationary cam member in said casing, a hammer member operated by said rotor shaft and engageable with said cam member, a tool operating shaft clutch frictionally engageable with said tool operating shaft and engageable with said hammer member, said tool operating shaft clutch freely shiftable in one direction relatively with said tool operating shaft, and control lever and link means arranged to release said tool operating shaft clutch from said tool operating shaft.

6. In an electric drill of the class described, the combination of a casing, an electric motor in said casing, a hollow rotor shaft for said motor, a tool operating shaft reciprocally mounted in said rotor shaft, a feedscrew internally of said tool operating shaft and operatively engageable therewith for longitudinally shifting said tool operating shaft in' said rotor shaft, said tool operating shaft extending outwardly from said casing, and a retractible cover for said tool operating shaft at its outwardly extending portion.

'7. In an electric drill of the class described, the combination of a casing, an electric motor in said casing, 'a hollow rotor shaft for said motor, a tool operating shaft reciprocally mounted in said rotor shaft, a feed screw internally of said tool operating shaft and operatively engageable therewith for longitudinally shifting said tool operating shaft in said rotor shaft, means for holding and guiding said tool operating shaft in conforming revoluble relationtherewith, cooperative gear means in connection with said rotor shaft and said feed screw and clutch means in connection with said cooperative gear means for reversing the revoluble operation of said feed screw, and trip means in operative relation with said gear means for automatically disengaging said clutch means.

8. In an electric drill of the class described, the combination of a casing, an electric motor revolubly mounted in said casing, a hollow rotor shaft for said motor, a tool operating shaft reciprocally mounted in said hollow rotor shaft, a hollow feed screw positioned in said tool operating shaft arranged to longitudinally shift said tool operating shaft in said hollow rotor shaft and means in said casing for forcing matter through said hollow feed screw.

9. In an electric drill of the class described, the combination of a casing, an electric motor revolubly mounted in said casing, a hollow rotor shaft for said motor, a tool operating shaft reciprocally mounted in said hollow rotor shaft, a hollow feed screw positioned in said tool operating shaft arranged to longitudinally shift said tool operating shaft in said hollow rotor shaft, means in said casing for, forcing matter through said hollow feed screw, and gear means operated by said rotor shaft and arranged to reverse said feed screw.

10. In an electric drill of the class described, the combination of a casing, an electric motor revolubly mounted in said casing, a hollow rotor shaft for said motor, a tool operating shaft reciprocally mounted in said hollow rotor shaft, a hollow feed screw positioned in said tool operating shaft arranged to longitudinally shift said tool operating shaft in said hollow rotor shaft, means in said casing for forcing matter through said hollow feed screw, gear means operated by said rotor shaft and arranged to reverse said feed screw, and clutch means in connection with said gear means arranged to reverse said feed screw.

11. In an electric drill of the class described, the combination of a casing, an electric motor revolubly mounted in said casing, a hollow rotor shaft for said motor, a tool operating shaft reciprocally mounted in said hollow rotor shaft, a hollow feed screw positioned in said tool operating shaft arranged to longitudinally shift said tool operating shaft in said hollow rotor shaft, means in said casing for forcing matter through said hollow feed screw, gear means operated by said rotor shaft and arranged to reverse said feed screw, gear means operated by said rotor shaft and arranged to revolve said feed screw, clutch means in connection with said gear means arranged to reverse said feed screw, and main control levers in connection with said clutch means.

12. In an electric drill of the class described, the combination of a casing, an electric motor revolubly mounted in said casing, a hollow rotor shaft for said motor, a tool operating shaft reciprocally mounted in said hollow rotor shaft, a hollow feed screw positioned in said tool operating shaft arranged to longitudinally shift said tool operating shaft in said hollow rotor shaft, means in said casing for forcing matter through said hollow feed screw, gear means operated by said rotor shaft and arranged to reverse said feed screw, gear means operated by said rotor shaft and arranged to revolve said feed screw, clutch means in connection with said gear means arranged to reverse said feed screw, main control levers in connection with said clutch means, and hammer means in operative relation with said tool operating shaft.

13. In an electric drill of the class described, the combination of a casing, an electric motor revolubly mounted in said casing, a hollow rotor shaft for said motor, a tool operating shaft reciprocally mounted in said hollow rotor shaft, a hollow feed screw positioned in said tool operating shaft arranged to longitudinally shift said tool operating shaft in said hollow rotor shaft, means in said casing for forcing matter through said hollow feed screw, gear means operated by said rotor shaft and arranged to reverse said feed screw, and hammer means in operative relation with said tool operating shaft.

14. In an electric .drill of the class described, the combination of ,a casing, an electric motor revolubly mounted .in said casing, .a hollow rotor shaft for said motor, a tool operating shaft reciprocally mounted in said hollow rotor shaft, a hollow feed screw positioned in said tool operating shaft arranged to longitudinally shift said tool operating shaft in said hollow rotor shaft, means in said casing for forcing matter through said hollow feed screw, gear means operated by said rotor shaft and arranged to reverse said feed screw, hammer means in operative relation with said tool operating shaft, and a tool operating shaft clutch engaging said tool operating shaft and arranged to receive hammer impulses from said hammer means.

MAX J. DEMO. 

